Beta & Volatility

Key term: beta

When two companies are paired up in a matchup, one question matters as much as which direction each will move: which one is likely to move by more? That's what beta measures — how much a stock tends to swing compared to the overall market.

A beta of 1.0 means a stock roughly tracks the market: a 1% move in the broader market tends to produce something close to a 1% move in that stock. A beta above 1.0 means the stock swings harder than the market in both directions — a beta of 1.5 suggests a 1% market move often becomes something closer to a 1.5% move in that stock. A beta below 1.0 means the opposite: a steadier stock that tends to move less than the market around it.

It's important to be precise about what beta does and doesn't tell you. It says nothing about which direction a stock will move — only how forcefully it tends to move once something happens. A high-beta stock isn't more likely to go up; it's more likely to go up a lot, or down a lot.

In a head-to-head matchup, the higher-beta company is usually the bigger mover on the day, for better or worse — more likely to deliver a large win, and just as likely to deliver a large loss if things go the other way. It's a measure of magnitude, not of direction.

In the daily game

Beta lives in the Game-Day Setup section of every matchup — compare the two companies' beta values to see which one is set up to be the bigger mover today.